Uncovering the Comorbidity of Mood and Substance Use Disorders

Researchers have been investigating the comorbidity of mood and substance use disorders for decades. In the 1980s, the National Institute of Mental Health’s Epidemiologic Catchment Area (ECA) study found that, among individuals with a mood disorder, 32 percent also had an addiction or substance abuse problem. Among individuals specifically struggling with major depression, 16.5 percent had an alcohol use disorder, and 18 percent had a different drug use disorder. Among people with bipolar disorder, substance abuse disorders were found in 56 percent of the population.

In recent years, clinicians have found that it is less helpful to treat one disorder followed by the other than to treat the comorbid conditions together. Treatment programs are continually developing effective methods of helping people who struggle with comorbid mood and substance use disorders, although this is a relatively new phenomenon in the realm of substance abuse treatment.

Types of Mood Disorders, and How They Correlate to Substance Abuse

Mood disorders are mental illnesses involving serious changes in a person’s mood. According to Mental Health America, 20 percent of the US population reports at least one symptom of depression in any given month, while 12 percent report two or more in one year. Bipolar disorder affects roughly 1 percent of the population. In most mood disorders, symptoms of depression are common, and these are often used as a tool to uncover the underlying condition; however, according to the Substance Abuse and Mental Health Services Administration (SAMSHA), anxiety is the most common mental illness, followed by depressive disorders.

Depression: The term depression covers conditions like major depressive disorder and persistent depressive disorder. Symptoms of depression include loss of interest in activities, changes in sleep and appetite, feeling guilty or worthless, and, in extreme instances, suicidal ideation. People who struggle with depressive disorders might self-medicate with alcohol or cocaine, most commonly. However, all drugs of abuse are found to have some correlation with making the person feel depressed at some point during the addiction. Depression is also sometimes a symptom of withdrawal.

Bipolar disorder: There are a few different categories of bipolar disorder, including cyclothymia, which is considered a mild form of bipolar. Over half of individuals with bipolar disorder also abuse substances, most often during cycles between mania and depression. In some cases, drinking alcohol during a manic episode can induce the depressive episode, and sometimes lead to a relapse of a full depressive episode. Sometimes, people with bipolar disorder will abuse stimulants like cocaine to relieve the intense depressive symptoms, although this is less likely to induce bipolar-related mania and instead correlates with a drug-induced mania.

Anxiety: The subtypes of anxiety include social anxiety disorder, post-traumatic stress disorder, and panic disorder. The most common substance of abuse among people with anxiety disorders is alcohol, which these individuals self-report helps them to calm down. However, abusing alcohol typically makes symptoms of anxiety worse. With PTSD and social anxiety disorder, abuse of alcohol typically begins after the onset of the mood disorder. In the case of panic disorder, however, alcohol abuse most commonly begins prior to the onset of panic attacks.

Causes of Comorbid Mood and Substance Abuse Disorders

Substance abuse and mental health intertwine in ways that researchers are only recently beginning to understand, but there are some general causes or reasons behind the link:

Self-medication: The symptoms of a mood disorder can feel so intense that the individual needs to take the edge off the sensations or change their mood. Abusing alcohol leads to feelings of relaxation, then depression, while abusing cocaine alleviates depression and increases exhilaration, then mania. Although there are numerous other drugs of abuse – increasingly, opioid painkillers, for example – alcohol and cocaine are the two of the most common that are used for self-medication.

Early onset: People who are predisposed to both a mood disorder and an addiction can precipitate the early onset of one condition when the other takes effect. This is most commonly seen in those who struggle with substance abuse, and it can trigger a mood disorder.

Genetics, family history, or environmental factors: People whose families have a history of mood disorders are likely to struggle with both mood disorders and substance abuse, and people whose families struggle with addiction are more likely to develop a mood disorder as well as substance abuse problems. Whether this is a genetic predisposition or an environmental condition is little understood, but the correlation is strong.

Susceptibility: People who have a mood disorder are more likely to feel the effects of intoxicating substances, especially the negative effects, which can lead to a cycle of self-medication and increasing mental illness.

Before understanding how these symptoms appear together, it is important to understand how symptoms present in the different disorders, separately.

Symptoms of major depressive disorder: This is typically diagnosed after a person has struggled with depression for two years or more. Experiencing anhedonia or lack of pleasure along with guilt or worthlessness are common symptoms of depression. When these continue for years, or occur in two-week episodes frequently for two years, the individual likely struggles with major depressive disorder.

Bipolar disorder: This condition is characterized by rapid swings between mania and depression, often followed by a long period of depression. Sometimes, individuals with bipolar disorder can experience mania, but not depression.

Anxiety disorder: Although each subtype of anxiety disorder has slightly different symptoms, general overarching symptoms include persistent feelings of restlessness or anxiety, feeling like there is impending danger, rapid breathing and increased heart rate, trouble sleeping or concentrating, feeling sick to the stomach, avoiding activities that trigger anxiety, and experiencing panic attacks.

The correlation between mood disorders and substance use disorders is very strong. According to the Anxiety and Depression Association of America, once these conditions become comorbid, they feed each other. Statistically, 20 percent of people who struggle with an addiction have an anxiety or mood disorder, and 20 percent of people with a mood disorder also struggle with substance abuse.

In a study conducted by the authors of “Substance Use Disorders in Patients with Anxiety Disorders,” college freshmen with anxiety disorder had a greater chance of developing alcohol dependence than their peers without anxiety disorder, within 4-7 years. Another study found that 18-30 year olds with anxiety disorder were 2-3 times more likely to develop an addiction, compared to their peers.

A study reported on by Primary Psychiatry on substance abuse and mood disorders in general found that mood disorders accounted for 71 percent of mental health diagnoses among individuals struggling with methamphetamine addiction.

According to SAMSHA, in 2014, around 340,000 adolescents between 12 and 17 years old reported both a major depressive episode (MDE) and a substance use disorder (SUD). This age group was more likely than their peers without MDE to regularly use marijuana, psychotherapeutics like Xanax and Ambien, hallucinogens, and inhalants. About 1.6 percent of those with past-year MDE also smoked cigarettes, and 1.8 percent with past-year MDE were heavy alcohol drinkers in the past month.

Symptoms of Mood Disorders and Substance Use Disorders

When a person struggles with an addiction, long-term physical effects of leaving this condition untreated can damage the brain and internal organs.

Increased sensitivity to developing an addiction to other substances due to changes in the brain’s risk/reward system

Tolerance to the drug, so more is taken regularly

Heart disease from high blood pressure

Increased risk of STDs and other problems due to lowered inhibitions

Ulcers in the gastrointestinal tract

Permanent damage to the nose or veins, depending on ingestion route

High risk of stroke

Bleeding in the brain

Memory loss

Regardless of the drug of abuse – whether cocaine, alcohol, or any other substances – the long-term effects of continued use can be severe. They can also reach to all areas of life – health, relationships, finances, career, etc.

Although it is obvious that long-term abuse of intoxicating substances would damage the body, mental health issues can lead to physical and mental changes as well.

Damage to the cardiovascular system due to increased adrenaline rushes

Weakened immune system

Consistent stomach pain or irritable bowel syndrome

Appetite changes

Low sex drive

Each of these conditions by itself, when left untreated, can pose long-term, chronic health risks and an increased risk of early death. When combined, these conditions exacerbate each other, and the risk of dying early increases.

Getting Help for Comorbid Disorders

Clinicians focus on behavioral approaches, in addition to pharmacological options as needed, when treating individuals with comorbid substance use and mood disorders. Cognitive Behavioral Therapy has been shown to be among the most effective treatments, as it addresses damaging thought patterns related to both the substance abuse and the mood disorder.

Whether a person struggles with depression due to withdrawal or substance abuse triggered by depression, most medical professionals will prescribe a small dose of an antidepressant to help ease those symptoms. Depression is one of the more successfully medicated mental illnesses, and it is easier to monitor symptoms of the mental health problem to see if the individual is improving. Though medications are often used in treatment, they do not “cure” either disorder; they must always be used in conjunction with therapy to manage the co-occurring issues.

Although attitudes toward comorbid conditions are changing, the overall healthcare system right now typically treats substance abuse and mood disorders separately. This is now viewed as inefficient, and medical professionals are pushing for change. Physicians tend to treat mental health concerns, while many types of providers will work with patients struggling with substance abuse. Finding a better way to get these two groups to work together will benefit people struggling with comorbid mood and substance use disorders.